sel
0
cons
X
sel
s
cons
sel
X
Z
dbl1
s
s1
s1
dbl1
X
sel1
0
cons
X
sel1
s
cons
sel1
X
Z
quote
s
s1
quote
X
dbl
0
0
dbl
s
s
dbls
nil
nil
dbls
cons
cons
indx
nil
nil
indx
cons
cons
from
cons
dbl1
0
01
quote
0
01
quote
dbl
X
dbl1
X
quote
sel
X
Y
sel1
X
Y
2.2
NaTT
certifiable-1.6